Strength of Bolted Lap Shear Connections with Advanced High-Strength Steel Sheets

Abstract

The objective of this work is to investigate the strength of bolted lap shear connections with advanced high-strength steel (AHSS) sheets and the effects of steel ductility on bolted connection behavior. An experimental study on AHSS bolted lap shear connections has been conducted, involving six different steel sheets that have nominal yield stress ranging from 340 to 1,200 MPa and ductility ranging from 3% to 20% in elongation. Four limit states are investigated: bearing, tilting/bearing, net section, and end tear-out. The connection strengths obtained from the tests are compared with strength predictions from relevant design specifications (AISI S100, AS/NZS 4600, EN-1993-1-3) and proposals in the literature. Connections with specific low-ductility AHSS sheets cannot reach full design strengths. Extending the strength reduction factor in the current AISI S100 specification to AHSS sheets is found to provide an adequate correction. Based on the test data, two new continuous strength reduction factors are proposed, one based on ductility as measured by ultimate elongation and a second utilizing true fracture strain as the ductility measure.